Duplexing telegraph-lines.



'No. 888,511. PATENTED MAY 26, 1908.

' I. KITSEE.

DUPLEXING TELEGRAPH LINES.

APPLICATION FILED AUG. 9, 1906.

WITNESSES:

INVENTOR NITED STATES PATENT OFFICE.

ISIDOR KITSEE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO WILLIAM J. LATTA, OF PHILADELPHIA, PENNSYLVANIA.

DUPLEXING TE LE GRAPH-LINE S.

Specification of Letters Patent.

Patented May 26, 1908.

Application filed August 9, 1906. Serial No. 329,885.

To all whom it may concern:

Be it known that I, IsIDOR KITsEE, citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Duplexing Telegraph-Lines, of which the following is a specification.

My invention relates to an improvement in du leXing telegraph lines.

It ias more special reference to lines with great capacity, such for instance as submarine or subterranean cables.

It is well known, that on such lines telegraphing with a straight current is out of the question and both polarities have to be employed to transmit messages.

()n the submarine cable today, the double key is used, one key adapted to impress a positive and one key adaptedto' impress a.

negative impulse on-the line. It was found after careful experiments, that it is advantageous to transmit with the aid of reversals, that is, im ulses alternately of opposite polarity, and that if the impulses are only momentary and are always alike in duration and intensity, the best results are obtained. Such system is called true reversals and this, my invention, is more specially adapted to such system.

On submarine cables, an artificial cable is employed for each station, if thecable should be duplexed; and the instruments are placed between a bridge joining the real with the artificial cable. This arrangement has its disadvantages the artificial cable is very cumbersome and costly and as the electric properties of the cable pro er are always changing, the condensing e 'ect and resistance of the artificial line has also to be changed.

It is the aim of my invention to dispense with such artificial cable and toproduce a system whereby telegraphic lines, even such as the submarine cable, may be duplexed with the aid of a simple local contrivance.

In the drawing, Figure 1 is a diagrammatic view of a line of transmission with two stations and my duplexing arrangement attached to each station; Fig. 2, is a section of the device used here for dupleXing purposes. 1 is the line of transmission connected to the stations A and B; each station is provided with the device adapted to transmit reversals. This device embraces the sources voltaic or straight current.

of current 7 and 15, here shown as two and one cells respectively, but it is obvious that the number of cells has to vary to suit requirements. Between the two sources of current is inserted the condenser 14 and the source 7 is provided with the shunt comprising the wires 13 and 9, and the key 11. The line is grounded at 16.

As a receiving device, the well-known siphon recorder is here shown in conventional sign, the glass siphon being omitted but, whereas, normally this instrument comprises only one coil, the instrument used for my purpose comprises two coils and the parts of this instrument are designated as follows: The permanent magnetic field 2, the normal coil 4, and the, as I call it, auXiliar coil 3. The normal coil is connected through wires 5 and 6 in series with the line of transmission each stationis also provided with the duplexing device, a device adapted to nullify the signal ing impulses on the home instrument. This nullifying device embraces the inductorium 30 consisting of the primary 10 and the secondary 18; the primary provided with the terminals 23 and 2 1 and also with the means to adjust its relation to the secondary; the secondary provided with the terminals 21 and 22; the primary is connected in series with the shunt aforesaid and the secondary is connected through wires 19 and 20 with the auXiliar coil 3. The transmitting device is adapted to transmit true reversals, that is, impulses alternately of opposite direction, but always of the same duration and inten sity. When the line is idle, that is, the key 11 of the shunt not depressed, then an im pulse will flow from the source 7 in the direction of its polarity, because this source is of greater electro-motive force than the source 15. But when the key is depressed, therefore the shunt around the source 7 established, the source 15 will send an impulse over the line in accordance with its own polarity and as the same is in opposition to the polarity of 7, this impulse will be in opposition to the former impulse. Both impulses will only be momentary on account of the presence of the condenser 14 in the line, for it is wellknown that as soon as a condenser is charged to the potential of the source connected to it, it is an effectual bar to the further flow of a In transmitting therefore, messages, the operator manipulates his key in the same manner as the Morse operator manipulates his key on land lines: He depresses the lever for a short period to transmit a dot and for a longer period to transmit a dash. In reality, only short impulses, as said above, are flowing over the line but the time unit the key is depressed differentiates between the dot and dash. I11 duplexing this line, it is necessary to nullify the home-signaling impulses on the home-receiving device and to attain this object, I have recourse to the arrangement whereby as soon as the key is depressed, an impulse will be generated in the secondary connected to the coil 3 and will flow in this coil in opposition to the impulse from 15 in the coil 4, thereby nullifying its effect When the key is opened, an impulse from 7 will flow over the line in opposition from the former impulse, but at the same time, through the ceasing of the flow of the current through the primary, an impulse will be generated in the secondary opposite from the former impulse and will flow through the coil 3, again nullifying the effect of the new signaling impulse.

In the drawing, I have illustrated the resistance 8 inserted in the region of the shunt.

It is obvious, that as the primary coil is ad justable, the relation between said coil and the secondary may be varied to suit requirements, and the value of the induced impulses generated may, therefore, be increased or decreased at will.

I have illustrated and described my duplexing arrangement as applied to a line provided with means to transmit true reversals but it is obvious that the transmitting means may differ in accordance with requirements.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a telegraphic system wherein the in coming impulses are received with the aid of a movable coil inserted in the line of transmission, a second movable coil therefor, a local circuit for said second coil, in combination with means to transmit impulses adapted to move the first named coil in one direction and in further combination with means adapted to move the second coil simultaneously in opposite direction.

2. In a telegraphic system, a transmitting and receiving station comprising transmitting means and receiving means, said receiving means comprising stationary core and two movable coils, the transmitting means comprising means to transmit one impulse over the line and to transmit simultaneously a second localized im ulse, the first impulse flowing through one 0' said coils and the second im ulse flowing through the second of said coi s, each impulse tending to nullify the effect of the other impulse.

3. In tele'graphy, a receiving device comprising stationary cores and two movable coils, one of said coils inserted in the line of transmission, the second of said coils connected to the secondary of an inductorium and means to generate in said secondary an impulse simultaneously with an impulse transmitted over the line, both of said impulses tending to move the coils in opposite direction.

4. In duplexed telegraphy, a line of transmission and two stations therefor, each station comprising receiving, transmitting, and duplex device, the receiving device comprising two movable coils, a stationary core for same, one of said movable coils connected to the line of transmission and, the second of said movable coils connected locally to the nullifying device, the transmitting device com prising means to transmit simultaneously two impulses, one impulse adapted to flow over the line and through one of said coils, the second impulse adapted to flow locally through the second of said coils, one of said impulses nullifying the effect of the second of said impulses on the receiving device.

5. I11 combination with a line of transmission and two stations therefor, means to nullify the effect of the signaling current on the home-instrument, said means embracing an inductorium, a source of current for the primary and means to operate the same, a movable auXiliar coil for the receiving device and means to connect said movable auXiliar coil to the secondary of said inductorium.

In testimony whereof I affix my signature in presence of two witnesses.

ISIDOR KITSEE.

Witnesses:

MARY C. SMITH, ALVAH RITTENHOUsE. 

